Smart Speed Bumps
A pair of designers Jae-yun Kim and Jong-Su Lee created a “smart” speed bump. This speed bump actually reacts to the traffic that crosses over it.
A small damper built inside the speed bump flattens out the bump when slow moving traffic crosses over it. On the other hand, the damper holds firm when a faster vehicle speeds over the speed bump.
This design makes the speed bump more emphatic to speeders than to non-speeders.
Read more here: http://www.yankodesign.com/2008/12/11/speed-bumps-that-flatten-for-slow-speeds/